A 'polar vortex' in the summer? How a chunk of arctic air will cool off CNY next week

Polar Vortex. These two words probably conjure up memories of the bitter cold, ice, and snow we experienced last winter. They probably aren't the words you expect -- or want to hear -- in July. Yet, the term is getting quite the buzz once again. So, what is the polar vortex, what isn't the polar vortex, and what does it all mean for Syracuse-area weather in the next week?

What it is...and what it isn't
To understand the polar vortex, we first need to understand a bit about the global wind patterns. The global climate and weather patterns are driven by a pretty simple principle: cold air at the poles wants to move towards the equator, while warm air at the equator wants to move towards the poles. The result is a pattern of rising and sinking air and high and low pressure systems. At each of the poles, a semi-permanent area of low pressure sits and spins continuously. This is the polar vortex. In the winter, the low strengthens. In the summer, it weakens. But it is not a new phenomenon, having first been discovered by meteorologists in the 1850s. It is also not a cold, swirling storm of doom.

Another important feature in the global wind pattern is the jet stream. The jet stream is a current of strong winds, usually between 30,000 and 40,000 feet above the ground. The jet stream separates cold air to its north and warm air to its south. When the jet stream builds into Canada, we get warmer. When it dips into the Southeast, we get colder. The jet stream is also often a major factor in the development of the snow storms we see and it has a role in severe thunderstorms.

When the jet stream dives south in the winter, on occasion, a piece of the polar vortex can break off from the main low pressure and head south with the jet stream. This actually takes place fairly often, and is what happened this past winter. So while a piece of it breaks off and moves south, the vortex itself stays put over the Arctic. On rare occasions, the low pressure itself can get pushed south into Canada. Either way, the result is frigid air for the eastern two-thirds of the country.

Is it coming?
Some of the weather models do show a small piece of the weak, summer version of the polar vortex breaking off and heading toward the Great Lakes region. The result will likely be at least a couple days of well-below-normal temperatures. Relative to average, it will be similar to some of the cold air outbreaks that impacted the area this winter.

Instead of high temperatures in the teens though, high temperatures may get stuck in the 60s next week, especially on Wednesday and Thursday. Bitter cold in winter...but a nice break from heat (and thunderstorms) in the summer.